1. Field of the Invention
This invention relates to an extraction cleaning machine and, more particularly, to an upright extraction cleaning machine.
2. Description of Related Art
Upright extraction cleaning machines have been used for removing dirt from surfaces such as carpeting, upholstery, drapes and the like. The known extraction cleaning machines can be in the form of a canister-type unit as disclosed in U.S. Pat. No. 5,237,720 to Blase et al. or an upright unit as disclosed in U.S. Pat. No. 5,500,977 to McAllise et al. and U.S. Pat. No. 4,559,665 to Fitzwater.
Current upright extraction cleaning machines can be made easier to use by limiting the weight and number of components, such as fluid storage tanks, on the pivoting handle of the upright cleaning machine. Reducing the weight that a user must support as the handle is tilted rearwardly can also lower the center of gravity for the machine, which results in a better feel to the user.
Furthermore, the current extraction cleaning machines can be made easier to use and better adapted for a variety of cleaning conditions. For example, none of the current extraction cleaning machines includes an elevator responsive-to-handle position for restraining a floating roller-type agitation brush, which is automatically height adjustable in response to changes on the surface being cleaned. Another problem inherent with the known extraction cleaning machines is the difficulty of filling and emptying the fluid supply chamber and fluid recovery chamber, particularly with bladder-within-a-tank type assemblies. Further, none of the current upright extraction cleaning machines are simply convertible to a pre-spray applicator for directing cleaning solution to and agitating the surface to be cleaned without applying suction. Finally, current extraction cleaning machines do not use a the same motor to drive an agitation brush as well as an impeller. In some cases a separate motor is used. In other cases, a turbine is used to drive the agitation brush or brushes which diminishes the suction power available to extract the dirty solution from the floor surface.
A more recent development in the extraction cleaning industry is the use of steam or hot water as a cleaning agent. The cleaning machine incorporates a boiler or other means for generating steam or hot water, which is pumped to an applicator where it is brought into contact with the surface being cleaned. Because the steam is airborne, it may be unsafe to include detergents and the like in the cleaning solution. Further, while the steam systems have the advantage of creating a temperature that effectively kills a wider range of microbes, bacteria, microorganisms, and mites, the steam systems generally suffer from poor cleaning performance. Additionally, the high power requirement for generating steam may not be sufficient with ordinary 120V power supplies for running a vacuum motor as well as the steam generator, so cleaning performance is further hindered. Also, by adding a heater to a fluid supply chamber, the user may be inconvenienced by the amount of time required to heat the contents of the supply chamber to the desired temperature. Conversely, conventional detergent cleaning systems are somewhat effective at cleaning surfaces, but could be made more effective by raising the temperature of the cleaning solution to some temperature below the boiling point. There is an optimal temperature at which cleaning performance is maximized without causing damage to carpets or setting stains. This temperature is around 150° Fahrenheit.